Grinding machine



G. F. WILSEY GRINDING MACHINE I Sept. 3, 1935.

Filed Aug. 30, 1935 3 Shets-Sheet l 'IAIumm EEF- dual/"41:0

Patented Sept. 3, 1935 STATES PATENT OFFICE Application August 30,

11 Claims.

The invention has for its object to provide a sturdy, simply constructed machine, preferably of the portable type adapted to be secured in a vise or mounted upon a standard, and is particularly applicable to the grinding of the ends of piston rings to provide the necessary clearance gap and for grinding the faces of contact pins and points of timers, distributors and like devices employed in the ignition systems of internal combustion engines.

The invention is illustrated in some of its various applications in the accompanying drawings, in which:-

Fig. 1 is a plan view of the machine as employed in grinding the ends of piston rings.

Fig. 2 is a section on line 2-2 of Fig. 1.

Fig. 3 is a section on line 3-3 of Fig, 1.

Fig. 4 is a section on line 44 of Fig. 1.

Fig. 5 is a plan view of the machine in its application to the grinding of the faces of electrical contacts employed in ignition systems.

Fig. 6 is a side elevation.

Fig. 7 is a section on line of Fig. 5.

Figs. 8 to 12 are details illustrating the mode of application of the machine to the grinding of contact points of timer switch arms of various forms.

Figs. 13 and 14 are an elevation and a plan View of means for supporting and grinding the face of a contact pin,

Fig. 15 is an enlarged perspective view of the portion of the apparatus for supporting the timer switch arms.

Referring to the drawings, I indicates the bed plate in the form of a relatively long narrow bar of steel or the like fast to one end of the top surface of the block 2, adapted to be secured in a vise or upon a standard,as indicated in dotted lines in Figs. 5 and 6. To enable the block to .besecured to a suitable post or standard, said block is provided with an opening 4 near its v.outer end through which the post or standard passes and in which opening the post or standard is locked by means of a set screw 3. The bed plate I is provided with a longitudinal slot 5 in which the grinding wheel operates and is finished on its end remote from the support with longitudinal rabbets l, l, which constitute the guides for the transverse work table to be hereinafter described.

Secured to the inner end face of the block 2 is a segment plate 6 provided with a series of holes 6' adjacent its peripheral edge and pivoted on a stud 8 mounted at the top of the segment plate is a hanger plate 1 to which is attached a bracket 1933, Serial No. 687,500

9, which supports an electric motor l0, upon the shaft ll of which is mounted the grinding disk I2, which, as stated, projects upwardly through the slot 5 in the bed plate I. As indicated in Figs.

2 and 3, the hanger plate 7 is adapted to be adjustably connected to the segment plate 6 so that the motor and the grinding wheel |2 may be swung to various positions to cause the grinding wheel to extend through the slot 5 in the bed plate either normal to the plane of the latter or 1 angularly disposed to the normal, and preferably at 45' on either side of the normal depending upon whether the end faces of the piston rings are to be ground square or at complementary angles of 45. In order to lock the motor securely in its various positions of adjustments, there is provided a pin l5 mounted in an opening in the plate I and adapted to selectively engage the holes 6' in the segment plate 6, said pin being operated by a handle l6 pivoted to the bracket 9 and actuated 20 by a spring l8. By pressingdown on the handle I6 and withdrawing the pin l5 from engagement with the hole 6' in the plate 6, the hanger and the motor l0 may be swung about the bolt 8 as a pivot, as indicated in dotted lines in Figs. 2 and 3. It will be understood that the motor may be swung either upwardly or downwardly from a horizontal position to adjust the grinding disk l2 to angular position on either side of its normal or perpendicular position. Slidably mounted on the bed plate I is a work holding table 20, the top surface of which is in the same plane as the top surface of the bed plate and the sliding engagement of the work table on the bed plate is effected by means of the rabbeted mid section of the work table engaging the bottom and side edges of the bed plate, the parts being secured together for relative sliding movement by means of plates 2| secured to the work table and engaging the rabbets on the bed plate, as more particularly 40 shown in Figs. 1, 4 and 5. Joumaled in bearings 2|, 2| on the opposite ends of the under face of the work table is a shaft 22 provided with a hand crank 25 at one end and having screw threaded portions 23, 23 intermediate its ends which are engaged by nuts 26 having integrally threaded studs 21 projecting radially therefrom and extending through longitudinal slots 26 in the work table, so that, when said shaft 22 is rotated in one direction, the nuts 26, 26 will move toward each other and, when the shaft is rotated in theopposite direction, the nuts will move away from each other. Each of the threaded studs 21 is provided with a set nut 28, which, in the form of the apparatus shown in Figs. 1 to 4,

is adapted to lock one of a pair of V-shaped clamps 29 to the corresponding nut, said clamping members 29, 29 being adapted to engage and compress a piston ring to the diameter necessary to permit the ends of the ring to be ground or cut away to afford exactly the requisite clearance space or gap, when the ring is applied to the piston and inserted in the cylinder in which the piston operates.

As indicated in Fig. 1, the machine is adjusted to cut or grind the ends of the piston ring with right-angled faces, that is to say; the surfaces of the ends being normal to the plane of the ring.

To effect this result, the piston ring is dropped" in position between the clamps 29, after the work table has been withdrawn toward the end of the machine, and the clamps set up by turning the handle and rotating the threaded shaft 22. When the clamps have been set up to compress the piston ring to the desired diameter, the work table is moved longitudinally of the bedplate until the split or gap of the ring straddles the grinding-wheel [2. The ring is then rotated by ihanda slight distance sufficient to bring one of the ends of the ring into engagement with the side face of the grinding disk and held against the same until the desired amount of metal has been removed from the end face of the ring,

whereupon the ring is rotated by hand in the opposite direction to bring the other face of the end of the ring into engagement with the opposite face of the disk 2 to cut away the necessary amount of metal fromlthis end of the ring, so thatthe two ends of the ring will be ground into exact parallelism and the total amount of the metal cut away'will provide the exact amount of clearance or gap required. After the ends; of the ring have been properly dressed, the clamps 29 are retractedby reversing the movement of the -i nbefore described, until the pin l5 snaps into one or the other of theend holes 6' in the segmentplate 6, so that the motor will be again locked to thesegment plate and the grinding disk l2 will occupy an angular position to one side or the other of the perpendicular, so that, when the ends of the ring are brought successively into engagement with the opposite face of the disk l2, the latter will grind away the ends on complementary bevels to provide the necessary clearance. It will be understood that the, motor is supplied with current by means of a cable connected by the usual coupling devices with the available current supply leads and that a suitable switch, such as l3, will be provided for starting and stopping the motor.

It will be understood that the grindingmaehine is adapted to other operations than the dressing or grinding of the ends of piston rings and, as exemplified in Figs. 5 to 15, inclusive, is shown associated with a special jig to effect the grinding or resurfacing of the faces of contacts of various types cf distributor and timing devices.

Referring more particularly to Figs. 5, 6 and '7, 38 indicates a generally rectangular plate adapted to overlie one end section ofthe work table 20 and an adjacent section of the bed plate l, said plate 38 beingprovided with an opening adapted to receivethe threaded stud 27 on the corresponding nut 26 and be locked in position by the set nut 28, the opposite angular end of said plate 30 having thereon a right-angled boss 3|, which engages the under face of the bed plate,

as indicated in Fig. 7. This plate 36 carries all of the instrumentalities necessary to support any of the various standard types of breaker arms employed in the timing apparatus of an ignition circuit of an internal combustion engine and also to support ordinary screw or pin contacts and move the contact to be ground into engagement with a lateral face of the grinding disk l2. For example, for the purpose of dressing or grinding the face of a contact pin or stud, there is mounted-on the top of the plate 38 a support 32 preferably made of brass or other soft metal to avoid damaging the screw threads of the pin or stud, which support has therein a transverse V- shaped slot 33 adapted toreceive the pin or stud, the contact end of whichis to be dressed or ground, said pin or stud beingiheld firmly in position in the V-shaped slot by means of a lever 3d pivoted on a transverse pin 35 mounted in a clevis section of the support, saidlever being actuated by a helical spring 36 interposed between the power end of said lever and a socket in the support '32, said spring tending toforce the opposite end of the lever downward into the transverse V-shaped slot 33. ,A set screw 31 engaging a threaded boss 38 on the'top of the plate 30 extends transversely of said plate in alignment with the longitudinal axis'of the V-shaped slot 33 and serves as an adjusting abutmentfor the pin or stud occupying. the said slot, in the manner and form shown in Fig. 14. In grinding or resurfacing the contact end of the pin or stud,.the latter is placed inthe V-shaped groove'33 and the set screw 31 operatedto engage the outer end of the stud, so that the inner or contact end of said stud projects beyond the inner edge of the plate 30- and the support 32. When thisadjustment has been made, the lever 34 isrelease'd, so that the spring 36 will force the opposite" end of' the lever into firm engagement with the pin' or stud to be ground. The worktable 2|] is then' moved along the bed plate I toward the grinding wheel l2'.until the pin or stud to be ground is opposite the lateral face of the grinding wheel, after which the crank handle 251s operated to move the plate 30 inwardly and longitudinally of the'work table until the end of the stud or pin engages the lateral face of the grinding wheel. ''By continuing to turn the crank handle 25 by slow increments, the stud or pin will be fed toward'the grinding wheel until the desired amount of metal on the contact end 'of the stud or pin has been ground away, after which the pin or studrmaybe removed by depressing the latching' lever 34.

To adapt the device to the'g rinding of contacts of circuit breaker arms of various standard makes, the particular coordination illustrated in the enlarged detail in Fig. 1'5'is employed. This comprises agenerally link-shaped guide 46 secured to the top of the angular plate 30 and adapted to suppo-rt'a spring plunger in various positions of longitudinal adjustment in the'slet of said guide 40. The spring plunger includes a spool-like element 50 having flanges 5i" and 52, which engage opposite edges of the guideyin whichlelement 50 is mounted a pin 53 having a tapered and enlarged inner'en'd and a'button' or knob 54 on its outer end with a helical'spring 56 about its'reduced 'innerportion, which tends tomove the plunger inward toward the longitudinal axis of the bed plate and, therefore,

.toward the grinding disk.

Mounted on the top of the plate 30 and in general parallelism with the guide 46 is a generally Z-shaped element 52, the intermediate perpendicular wall of which is provided with a series of openings 64, 45, t6 and All, the vertical wall of the top horizontal wall of said element being provided with parallel slots .8 disposed on opposite sides of the hole 46 and an enlarged opening 39 above the opening 4?. The guide 48 is provided with a tranverse slot 4| in its upper face. These various holes, slots and openings are for the purpose of permitting certain types of the breaker arms being supported in proper position to have the contacts on said arms engaged with the lateral face of the grinding disk. For example, as shown in Fig. 10, a generally arc-shaped breaker arm provided with an enlarged contact button on one end thereof is clamped in position by engaging the contact button with the hole #5 in the Z-shaped support 42 with the arcuate portion of the arm occupying the slot 4! in the top of the guide 43, the spring plunger being adjusted laterally in the guide 48 until it is in alignment with the right-angle bend on the breaker arm immediately in the rear of the contact button. The spring plunger serves to hold the breaker arm firmly in position with the contact on the lower end thereof projecting through the opening 45, so that, when the plate 3% is fed transversely of the work table by the crank handle 25, the contact on the end of the breaker arm will be moved into engagement with the grinding disk l2.

With a breaker arm of the type shown in Fig. 11, in which the contact button lies between two flanges, which latter are engaged with the slots G8 in a guide 32 with a contact button projecting through the hole 46, the spring plunger is moved to position in alignment with the contact button in the hole t6 and clamps the breaker arm firmly in position, so that the contact button will properly engage the lateral surface of the grinding disk.

With the particular form of breaker arm shown in Fig. 12, the contact button is engaged with the hole 4?, the adjacent portion of the arm being accommodated by the opening 49. In this case, the spring plunger is adjusted so that the end 53 engages the breaker arm immediately in the rear of the contact button and holds the contact arm firmly in position with the button projecting through the opening 41 in proper relation to engage the lateral face of the grinding disk.

There are certain other types of breaker arms which cannot be properly supported between the spring plunger and the guide 42 and it is, therefore, necessary to provide an additional support which takes the form of an inclined strut 68 se-- cured to the upper face of the plate 38 at one end of the link-like guide M], which strut has on its upper end a horizontal pin 6|, which is engaged by the eye on one end of the breaker arm, with the contact stud or button on the opposite end of the breaker arm engaging the elongated slot M in the guide 42. This slot is elongated in a perpendicular direction to accommodate breaker arms having the contact button spaced different distances from the eye or pivotal end of the arm. With this arrangement, the breaker arm is firmly supported in the manner and form indicated in Fig. 8.

Some of this general type of breaker arms have enlarged eyes at their pivot ends and, in such case, a bushing or thimble 62 is provided having an interior diameter to fit the pin BI and an exterior diameter to fit the eye in the end of the breaker arm. When not in use, this bushing or thimble may be conveniently-mounted on a stud or pin mounted on the top surface of the plate 33, as indicated in Fig. 5.

It will be particularly noted that in all these applications of the machine to the grinding of the contact buttons on the ends of the breaker arms, the breaker arms are firmly supported at at least two points, so that there is no danger of displacement of the breaker arm and, when once in clamping position, the proper dressing or grinding of the face of the contact button will be insured.

What I claim is:

1. A grinding machine, comprising a supporting member, an elongated bed plate secured to the supporting member and having a longitudinally extending slot, a motor driven grinding disk carried by said support and extending through the slot in said bed plate, a work table slidably mounted on said bed plate and projecting on opposite sides thereof, and oppositely movable means for clamping the work to said table in position to be engaged with a lateral face of the grinding disk.

2. A grinding machine, comprising a supporting member, a slotted longitudinal bed plate secured thereto, a motor driven grinding disk extending through the slot in said bed plate, means aifording a pivotal support for said disk permitting the latter to assume different angular positions in the slot relative to the bed plate, a work table slidably mounted on said bed plate, and means for clamping the work to said table in position to be engaged with a lateral face of the grinding disk.

3. A grinding machine, comprising a supporting member, a slotted longitudinal bed plate secured thereto, a motor driven grinding disk extending through the slot in the bed plate, a work table slidably mounted on said bed plate provided with slots, means for clamping the work to said table and in position to be engaged with the lateral face of the grinding disk, said means including a screw threaded shaft journaled on said work table, nuts on said threaded shaft having bosses extending through the slots in said work table, and clamping members secured to said bosses.

4. A grinding machine, comprising a supporting member, a slotted longitudinal bed plate secured thereto, a motor driven grinding disk extending through the slot in the bed plate, a work table slidably mounted on the bed plate and having a slot extending therethrough, and means for clamping the work to said table in position to be engaged with the lateral face of the grinding disk, said means including a screw threaded shaft journaled on said work table, a nut on said shaft having a boss extending through the slot in the work table, a plate secured to said boss and slidably mounted on the work table and bed plate, and work securing devices carried by said plate.

5. A grinding machine, comprising a supporting member, a slotted longitudinal bed plate secured thereto, a motor driven grinding disk carried by said support and extending through the slot in said bed plate, a work table mounted on said bed plate for longitudinal sliding movement relative thereto, a feed screw journaled longitudinally on said work table and movable therewith, a nut on said screw, a plate connected to said nut and slidable on said work table and bed plate, and clamping means on said plate for securing various forms of contact devices in position tobe engaged with the lateral face of the grinding disk.

6. A machine as described in claim 5, in which one clamping means includes a support having a work holding slot therein, a latching lever for holding the work piece in said slot, and a set screw forming an adjustable abutment for the work piece.

7. A machine as described in claim 5, in which the clamping means includes a perforated slotted guide and support on said plate substantially parallel with the inner edge of the latter, and a spring plunger mounted for longitudinal adjustment on said plate parallel to said guide and operating to clamp the work against said guide and support with the part of the work to be ground extending through one of the perforations in said support.

8. A grinding machine as described in claim 5, in which the clamping means includes a perforated and slotted guide and support on said plate substantially parallel with the inner edge of the latter, a spring plunger mounted for longitudinal adjustment on said plate parallel to said guide and operating to clamp the work against said guide and support with the part of the work to be ground extending through one of the perforationsin said support, and a strut on said plate having a longitudinal pivot pin extending above and parallel with the guide to suspend a work piece on said pin in position toengage the part of the work to be ground with the subjacent perforations in said guide.

9. A grinding machine, comprising a bed plate having a slot therein, a grinding disk extending through said slot, and a work table slidably mounted on said bed plate, said work table extending beneath the bed plate and having portions respectively projecting on opposite sides thereof. I

10. A grinding machine, comprising a bed plate having a slot therein, a motor driven shaft disposed below the bed plate and having a grinding disk extending upwardly through said slot, and'a Work table slidably mounted on the bed plate provided with portions projecting on opposite sides thereof, said work table and bed plate respectively having surfaces disposed in substantially the same plane for supporting the work.

11. A grinding machine, comprising a bed plate having a slot therein, a shaft having a grinding disk projecting through said slot, a motor for driving said shaft, and means affording a pivotal support for the motor to permit said disk to assume different angular positions with respect to the bed plate, the pivotal axis of said suppor being disposed above said shaft.

GEORGE F. WILSEY. 

